Discussion:

I have read of letting in more EGR gasses to fill the chamber with less fuel and thus displace some of the fresh incoming air and fuel and force a wider opened throttle to lower vacuum and pumping loses.

The trick is to balance the throttle VS the EGR gases to maintain speed. And a system to cut off the EGR when greater power and throttle is needed. I think a cutout switch to cut power at a higher throttle range.

This is considered a good way to improve MPG. I read that car makers are also putting in more EGR nowadays.

The only down side is the carbon crud build up though out the system.

I feel it needs either another way to do what the EGR does or a cleaning system to remove the crud.

I have been planning on water injection so adding water to the EGR stream might make steam to clean it and at the same time add some water as well.

Next question is what is the pressure inside the EGR system and where can I get a water pump to overcome that pressure?? And a one way valve(s) to prevent EGR Gasses getting into the water injection lines that can withstand the temps involved as well as I would like the one way valve(s) to be at the EGR pipes.

Feed back??

Rich

 

Just doing water/meth into the intake stream will help with keeping crud out of the plenum and runners. What are you trying to accomplish exactly, other than complicating something that doesn't need more complexity?

 

My main goal is a Low 1500/2000 RPMs at cruse in a 93 Chevy G20 Custom van running a 383, org 400 Crank and rods, the TPI system plus as much lean burn it will take.

Heads are stock 193 swirl ports, cam is a custom ground roller cam with a max life of 4.38" and running Rhords Roller lifters will pull 5% reduction.

Behind the engine will be a motorhome 4L80e an US Gear/Doug Nash Dual Range Overdrive which by the numbers will allow 80MPH at 1600RPMs.

Target is 20+ MPG.

Rich

 

sounds like you need a direct injected 5.3 and a 6l80e. think about it for a second, the engineers at gm had very similar goals as the sbc morphed into the ls1, and has had generational changes. i am starting to sound like a parrot, but the easiest way to get there really is doing a modern engine, trans, and ecu swap. as far as your egr thoughts and your ultimate goals consider this.. corporations with unlimited research and development budgets have had the same goal for over 30 years, i doubt a guy with an idea will do better on a one off project. sure you can enhance certain rpm ranges but it usually comes at the expense of less performance or undesirable side effects in other rpm ranges. everything you want.. is exactly what a direct injected 5.3 with 6l80e is. i am not trying to discourage you, if the personal challenge is what you want go for it, but it will probably wind up costing more than a low mileage pullout engine/trans ecu .

 

Perhaps your right.

But there is much to consider. Such a swap is MAJOR, they run VERY high fuel pressure, and there are so many other "improvements" you cannot see.

I feel that the current quest for greater HP with smaller engines are NOT looking for MPG, the tech has vastly improved yet cars do not make as good MPG as older cars could and did.

I am building a low 1000 to 5000RPM 383. I am adding an old trick Rhords roller lifters to allow two worlds low RPM power (400Foot pounds at 1500RPMs, and a mild power cam at 3K to 4.5K)

I am adding a second overdrive getting my final OD down to 5.6 lower than even the latest 10 speed.

SO I will have a engine with bottom end torque to easily pull a large G20 Van at 1500 RPMs at (with two OD) 80MPH.

My target is 20MPG plus. I hope to see 30MPG.

So as all effort by car makers is HP MORE HP and with smaller and smaller engine with no MPG improvements, THEY are not really working on it, just a way to make cars so complex NO ONE can work on them and so costly no one can afford to repair them and also so they do not last as did the car from around 2000 to 2010 did. Crown Vic's doing 300K plus.

As for why they do not do double ODs, too hard for customers to understand. I used to say too complex but nowadays too complex is no longer a problem...that boat has sailed.

Rich

 

Agreed! I would not waste my time on a 5.3L, dod lifters, direct injected carbon buildup prone garbage or the crappy 6L80E or 8 speeds that replaced them.

Your 1,500 rpm target is too low. EGR is near worthless for MPG. My Express van got better mileage when I turned off the EGR. Lean cruise is benificial but you need to be under light load. With the load you will see at 1,500 rpm you will never be in lean cruise. I have been knocking on 20 mpg highway at 75 mph with my 383, 4L85E and 3.73 geared 10.5" full floating 14-bolt in my 97. It turns 1,800 rpm at 60 mph, 2,100 rpm at 70 mph and 2,400 rpm at 80 mph. There is absolutely zero reason to be geared taller than that, even the slightest uphill grade has my MAP and thus cyl/air volume rising enough to kick me out of lean cruise. At 1,500 rpm all you are doing is pounding the rod bearings flat for less MPG.

 

Thanks for dropping by.

My response is based on everything I have read:

I would ask more about your 383: Specially about your engines torque peek? Standard practice is to build a 350/383 for a 2800 RPM torque peek and a 4500 to 6000 HP peeks.

Such an engine will indeed not perform well that far below its torque peek. It will be lugging.

Every aspect of my 383 has been geared for max torque at 1500/2000 RPMs.



I always felt the stock TBI 350 running into its stock 4L60e to its stock 3.43 rear end was just fine it its get up and go.

Its stock torque peek was a factory 2200 RPMs and seemed programed to get 14MPG at any speed, and did so the lest road trip from Phx to Sedona which is up and down some mountains and I was mostly keeping up with most of the other cars running between 75 and 85MPH.

A fair amount of the time in third. My MPGunio was reading around 14MPG and on the refillup it also came out to be around 14MPG.

Everything I have read seems to say like the old movie Field of Dreams, build it and they will come. Build your engine and gearing FOR as near to your engines torque peek and at your cruse speed.

I choose highway speeds of 75/80 MPH and built my engine so its torque peek will be at 2000RPMs so it will be strong at 1500.

And again everything I read stated that the common hot rod tricks HURT MPG, tricked out heads, large valves power cams, ETC. all make HP and torque but at higher RPMs and this will NOT make MPG.

I had a 2000 Mercury Grand Marques. Stock it made 30MPG at 65MPH/1700RPMs all day. It only had 200HP.

I now have a 2003 Crown Vic everything is the same: gearing ETC. BUT it now makes 240HP and MPG dropped to 25 at 65MPH.

The extra 40HP cost 5MPG. The power curve was moved up in the RPMs.

Here is my gearing chart:



I figure to start testing with the stock rear end and see how things go.

AS my old rear end is howling I plan on rebuilding it shortly and will hopefully will see that I can go to lower gearing to raising my top speed slightly higher.

Like this:





Lastly I was very concerned about "At 1,500 rpm all you are doing is pounding the rod bearings flat for less MPG." so first I had the clearance redone by a engine shop for 2.65, and I will be running a BBC oil pump to insure full pressure at 1000 up.

A few have said I am creating a gas power diesel.

Rich

 

I kind of hate to post this:

Perhaps you should have considered a baby engine with direct injection and 8 speed:



I of course do not have $40K to spend, and this a plain stock van, a custom version is nearly twice as costly.

Rich

 

On my testing:A last good steady MPG testing conditions: Will second overdrive work?

A fairly empty I 17 Freeway Sunday Morning at 4 am.

4AM I17 North from Cactus to 101 and south 101 to Cactus Temp 70Degrees

Two runs each way. No wind.

I have used the section of freeway for almost all my MPG testing. Using GPS I found there is a slight incline, I found I lost avg. 1MPG going north and gained 1 to 2MPG driving south.

Also at two locations were flags flying so I got a visible tell if there was any wind.

All of four cars I have tested this on:

A 2000 Mercury Grand Marques: 4.6 3.27 @30MPG @ 65MPH @1700RPMs

A 2003 Ford Crown Vic 4.6 3.27 25MPG @ 65MPH @1700RPMs

A 2003 Ford Explorer 4.6 3.73 30MPG @ 49MPH @ 1500 RPMs

A 2002 Ford Explorer 4.0 3.73 30MPG @ 49MPH @ 1500 RPMs

Lasting was 2003 2003 Ford Explorer 4.6 3.73 30MPG @ 49MPH @ 1500 RPMs

Speed checked by GPS, RPMs, MPG, GPH, engine Temp. Checked by MPG testing with a newly Upgrade Scan Gauge II, using trip MPG readings.

1AM I17 North from Cactus to 101 and south 101 to Cactus Temp 70Degrees

Two runs each way. No wind. Engine fully warmed up and running 190 degress.

Discovered that my real RPMs and Speed do not match the on line calculator so corrected rear end gears to match real world readings:

Took her out again tonight. 60MPH and 70MPH TRUE by GPS. I am concerned when the calculator was off.

SO reset by this real world readings:

50MPH 1521 = AVG 26/27MPG Reads like a 3.55 Rear end.

Recalculated 2nd Overdrive with 3.55: DOD Is Double Over Drive

42MPH in 5th @ 1270RPMs = DOD = 60MPH

45MPH in 5th @ 1380RPMs = DOD = 65MPH

49MPH in 5th @ 1480RPMs = DOD = 70MPH = 29MPG

52MPH in 5th @ 1580RPMs = DOD = 75MPH

56MPH in 5th @ 1700RPMs = DOD = 80MPH

59MPH in 5th @ 1800RPMs = DOD = 85MPH = 26MPG

Due to traffic I only got these lowest and highest readings: Even this early I was having a car or two climb up my rear end.

Lowest I read was 49MPH by GPS and got 29MPG and highest was 59MPH and read 26MPG. SO IF the SUV can get the same MPG at the Same RPMs then at the higher speed in double overdrive that will mean at 70MPH it will be doing 29MPG and at 85MPH getting 26MPG.

Of course these projections do not, cannot show what effects wind and rolling resistion will be and how they will affect the real world MPG. But I believe it will only be minor.+/- 1 MPG.

Of course this will only help with higher speeds, mainly on highways.

And the costs of building it and installing it will take some time to be paid off by the money I will be saving by the lowered costs of driving in gas savings.

So it is a cost VS benefits calculation, so the cheaper the cost the better.
I believe I can install a older Borg Warner devoiced R10 Overdrive into my 03 Explorer for around $500.00 to $1K.

My van is getting a US Gear dual range overdrive. About $1K to $1.5K.

Rich

 

I keep reiterating that you are going to pound your rod bearings flat because that is exactly what happens when an engine is forced to use extremely low rpm and high cylinder pressure to create enough torque to move a vehicle with inadequate gearing. My 383 will pull smoothly down to 1,200 rpm and does at very low throttle angle. As soon as the MAP starts to rise, I unlock the converter and or downshift out of the high engine load. My 383 makes good torque and still makes good hp. Just a reasonably accurate software model.

 

I will also state that the way I tried to model the effects od Rhoads lifters as well as tri-y headers was a failure on my part but the actual result was better than expected. Where the software model is showing peak torque at 4,500 rpm and peak hp about 5,700 rpm, with the torque converter locked up on the dyno it actually made peak torque at 3,100 rpm and peak hp at 5,600. The torque curve was almost table top flat from 2,000-5,000 rpm.

 

You calculations are off when it comes to speed and MPG especially pertaining to your van. Wind resistance increases exponentially. Double the speed and get 4x the wind resistance and the vans house like frontal area combined with your added top extension are going to catch wind like a parachute. It is going to take X amount of HP to pull your van into the wind. Lets say it takes 20 hp to move your van 40 mph. To move it 60 mph takes 40 hp. 80 mph is going to take 80 hp. That increased power has to come from somewhere. Either more raw engine torque or more rpm or a combination of the two. That is forgetting the fact that your additional overdrive is costing you torque production at the tires and costing you hp via reduced engine rpm at the same time. So lets take that 80 mph figure. With a stock van 350, 4L60E and 3.42s with a ball park 29" tall tire ots at say 2,400 rpm at 80 mph.. 80 hp and divide by 0.7 = ~114. Now back calculate the torque needed to make that HP. 114 x 5252 ÷ 2400 is 249.47. Now lets throw in your example. 80 hp / 0.6 = 133. 133 x 5252 ÷ 1960 = 357 tq. My example is in the simplest of forms, negating drivetrain and accessory loss. Even if your engine is capable of producing the torque needed to pull this gearing effectively the engine is going to be much more stressed every mile of its life.

 

I have read and heard that statement over and over about Vans and Trucks.

If that was true then it would be impossible for that tall non-Aerodynamic Heavier 2019 Express van powered by a Gasoline 4.3 V6 even with all the super tech and a 8 speed with its final gear ratio of .65 into 3.42 it would be running about 1400RPMs @ 55MPH and 1600 @ 65MPH.

So we have a heavier, less areo Express Van underpowered with a baby engine with nearly the gears and Low RPMs I am shooting for getting a EPA rating of 19MPG City and 29MPG Highway.

HOW did that happen??

As for my 93 G20:

About the not being blown off the roads, and of Aerodynamics:

I bought my 93 Star Craft Custom Van after having stock Chevy vans for decades (1978 till around 2005 when I bought the 93,) I was concerned that with the raised roof and side ground effects would make winds worst for driving.

I drove a 74 Chevy van full time during the 80s and crossed the US on many times, in the 90s and into the 2000s it was then a 78 van. Again we did a lot of road trips all over.

I was VERY used to fighting for control with cross winds and when passing or being passed by BIG RIGS. The bow wake of air would buffer and push my vans all over the road; I am sure near every Van owner knows what I am talking about.

My first road trip showed me that was NOT a problem. Cruising at 75 MPH I was over taking a Big Rig and I braced for the fight as I over took the cab…and..and WTF no fight, I breezed by this big truck….

Must have been a trick cross wind that stopped the bow wake of the big rig, BUT it happened again and again, almost no effects of passing trucks, and even when I was over took by even faster big rigs.

OMG The stream lining ground effects of the Star Craft panels which I loved for their LOOKS really works. I have had the van for 15+ years now and LOVE this effect.

I believe these ground effects keep air from under the van and I believe this nearly stops the effects of bow wakes and lowers the effects of cross wind on my G20 van.

But there seems to be a catch, as far as I have been able to learn this ONLY works with the old Star Craft costume vans, the newer look alike vans are not close enough to the ground for this to work.

Also I know big rigs do everything to help their MPG, and my van looks a lot like most newer rigs, and I see deflectors on the trailers that seem to cut air from under the trailers as well.

They would not add anything that did not work.

As these only came on these old van and many people really are not interested in completely rebuilding an old van my best suggestion is to either lower the newer vans or add to the front air dam and side skirting to get this effect.

This is a 2019 Express 3500 155 Van.


This is my smaller, lighter (unibody) much better Aerodynamic Van:




It is my belief that that the reasons this van does not get 25MPG is how it is rigged by its fuel control system.

That the stock TBI system along with a lack of torque at low cruse RPMs are the cause.

I hope to prove you and others to be wrong.

PS under some good advice I will be running a BBC oil pump for it's greater volume of oil, especially at my lower RPMs.

Rich